Traffic intersection



June 2l, 1960 A. o. cEDENo 2,941,454

TRAFFIC INTERSECTION Filed Oct. 21, 1957 2 Sheets-Sheetl 1 June 2l, 1960A. o. cEDENo 2,941,454

TRAFFIC INTERSECTION Filed Oct. 21, 1957 2 Sheets-Sheekl 2 Affare O//Vero Cea/eno INVENTOR.

\ MMM m 5 fm@ TRAFFIC INTERSECTION Arturo Olivero Cedeno, Ocampo 1073,Monterrey, Mexico Filed Oct. 21, 1957, Ser. No. 691,375

6 Claims. (Cl. 94-1) This invention relates to traic intersections andmore particularly to a trac circle for handling traic between aplurality of streets.

In traffic circles heretofore used it is necessary to turn onto and turnoff of the trafnc circle at the outboard lane. Thus, while interiorlanes are provided, their use*- fulness is greatly restricted and whenthey are used 1t is necessary for vehicles to be constantly shiftinglanes While at the same time watching tralilc entering the circle. Asentering traic must merge with traflic in the outboard lane, it isdifficult to get onto a crowded traic circle.

By this invention there is provided a traffic c1rcle in which theproblem of incoming merging tra'ic 1s eliminated, inside lanes are used,and traic can leave the circle from an inside lane. l

It is an object of this invention to provide a trailic circle in whichcars may enter the circle Without merging with other traiic. l

Another object is to provide a trac circle 1n which cars do not shiftbetween the several lanes of the circle.

Another object is to provide a traic circle in which cars may leave thecircle from an interior lane without first emerging with traffic in anexterior lane.

Another object is to provide a traic circle in winch a car may enter thecircle from any given street and exit onto any other given streetwithout merging with other traic or changing lanes while in the circle.

Another object is to provide a tratic circle as in the preceding objectfor serving at least four streets in which traic is conveyed about thecircle by a plurality of side-by-side winding lanes and the number ofwinding lanes at any one point is three less than the number of streetsserviced by the circle.

Another object is to provide a multi-level trac circle in whichautomobile trafc is handled between all streets without merging trafficor shifting lanes and in which over-height vehicles, such as trucks, arehandled separately to avoid the expense of spacing the levels asufficient distance to accommodate over-height vehicles.

Other objects, features and advantages of this invention will beapparent from the drawings, the specication and the claims.

In the drawings vwherein there are shown by way of illustration severalembodiments of this invention and wherein like numerals indicate likeparts:

Figurevl is a plan view of a traic circle constructed in accordance withthis invention and with a section of the upper level broken away toillustrate details of the lower levelthe streets of the intersectionbeing numbered successively 1 through 8 and outgoing lanes of eachstreet being numbered to indicate the origin of its traffic;

Figure 2 is a schematic view of a slightly modified form ofintersection; and

Figure 3 is a schematic view of a further modified form of intersection.

The Figure l form of intersection of this invention is characterized bya plurality of side-by-side winding lanes 10 through 17. One lane isprovided for each street serviced by the intersection and, therefore,their number will increase or decrease with the number of streetsserviced by the intersection. The lanes 10 through 17 receive incomingtraiiic from streets 1 through S, respectively, and convey it in acoiling or spiraling path toward the center of the intersection. Inother words, each of the lanes 10 through 17 coil toward the center ofthe intersection. The intersection is so constructed that traffic doesnot switch between these lanes, and permanent barriers may .be erectedbetween these lanes to prevent crossing of lanes.

The winding lanes 10 through 17 are provided at a common level and traicleaves these lanes by moving to another level after which it exits tothe streets again without crossing lanes and in the preferred formwithout merging traic. Thus, it will be seen that the intersection isprovided with an upper level indicated generally at 18 and a lower levelindicated generally at 19. In the form of intersection illustrated thewinding lanes are in the upper level.

Traffic leaves the Winding lanes of the upper level through a series oframps leading to the lower level. One ramp is provided for each windinglane at circumferentially spaced points labout the intersection. Thesepoints correspond in number to the number of streets serviced by theintersection. Thus, the group of ramps indicated generally at 2l, -whichmay be designated 21a through 21e, provide for transferring traffic fromeach winding lane llt), and I3 through 17 to the lower level. In likemanner the group of ramps indicated generally at 22 and comprising ramps22a through 22e provide for transfer of traffic to the lower level justbefore reaching street No. 3. In like manner groups of ramps areprovided about the circle for transferring trafic from the winding lanesof the upper level to each of the streets serviced by the intersection.These groups of ramps are shown at 23 through 23, and the individualramps of each group are numbered in the same manner as explained in thediscussion of groups 2,1 and 22.

Means for connecting the trac from each ramp at the lower level with thestreets is provided. Preferably these lanes are sufficient in number toavoid merging traffic.

lReferring to the lanes of the lower level servicing street No. 5, itwill be noted that separate lanes 29 through 35 are provided. Theselanes may be considered as part of or as a continuation of ramps 23`through 28, and in the claims they are so considered. By tracing traflicin theA lower level, it will be noted that lane 29 conveys tralic fromramp 24e to a point outboard of the winding lanes and then proceeds withthe winding lanes to a point adjacent street 6 where it turns under theincoming winding lane 15 and feeds traic onto the lane numbered 8 of istreet 6. By handling one lane of traiiic in this manner, the windinglanes which are at an upper level may be reduced in length. If it is notdesired to handle this trac in this manner, the winding lane 17 may beextended to a point opposite the termination of winding lane l0 anddischarge its traffic on the opposite side of street 6, that is lane 8of streetA 6 would be moved to the right-hand side of street 6 and wouldbe adjacent the curb of street 6 in leaving `the traic circle. Traiiicfrom winding lane 17 Wishing to turn onto street 5 proceeds along lowerlevel lane 30. In like manner, traiic from winding lanes 10, '11, 12 and13 proceeds along lanes 31, 32, 33 and 34 to the outbound lanes ofstreet 5.

in exactly the same manner eight times about the circle.

The illustrated form of circle as thus far explained han' Patente ,lune2l, 196i)l dles tratic between any street and six of the other seven4streets proceeding in a clockwise manner. Right turn traffic to theadjacent counterclockwise street is handled in a diierent manner."However, it will be understood that if desired, the winding lanes couldbe continued another step to handle traicbetween all oi the streetsserviced by the intersection.

It is preferred to construct the two levels of the traic circle with aclearance which will permit passenger cars only and to handleover-height vehicles, such as trucks, in a different manlief. For thispurpose the traflic circle may be surrounded by a bridge 36 whichfunctions in the manner of the usual traffic circle to handleover-height vehicles. Access ramps such as indicated at 37s'treet 5,provide for access and eiiit from the' surrounding bridge 36. Thisbridge also provides for right turn tr'ac between adjacent streets.While there will be sore merging ofntraic as right turn trafc moves ontobridge 36, it will be minor and unobje'ctionable. Right turn tratiicwill leave the bridge in a special lane such as 'shown at 38, street 4,and no diiiculty will be experienced in leaving the bridge. WhileV theentry and exit ramps for cach street may be separated, it is preferredthat they be sideby-side to minimize cost of the ramps leading to andfrom the bridge.

Thel handling of tratiic entering from street 5 is shown by lines of Vsand it will be traced here tofully explain the Way in which traiiiciiows on the circle. Tra'ic for each ofthe other streets is handled inthe identical manner. A motorist desiring to turn from street 5 tostreet 4 goes up ramp 37 and proceeds to the right as indicated by thearrows and leaves in lane 38 of streetl 4. A motorist de'- siring toturn onto any of the other streets proceeds in the two outboard lanesnumbered 5 onto winding lane 14. If it is desired to turn onto streetV6, the ramp 25a is entered to drop to the lower level. From the lowerlevel a lane 34 is provided which connects with the outgoing lanenumbered 5 of street 6. If it is desired to leave the circle at street7, the motorist continues along winding lane 14 to ramp 26h. A lane 33connects ramp 26h with the outs going lane 5 of street 7. lf desired,the motorist may bypass ramp 26b and proceed to ramp 27C which leads tostreet 8. Ramp 27 is connected by a lane 32. with lanev numbered 5 ofstreet 8. If desired, ramp 27C may be bypassed and the motorist mayproceed to ramp 28d. By dropping down ramp 28d and proceeding along lane31, the motorist may leave the circle and eXit on lane Svof street 1.Ramp 28d may be bypassed and the motorist may proceed along .windinglane 14 to ramp 21e. From ramp 21e the motorist may enter lane 30 toproceed to lane 5 of street 2., or he may enter lane 29 and proceed tolane 5 of street 3. in addition to the directional Vs, there is alsoshown a number of automobiles traveling like paths beginning at lane 6.The automobiles shownV in solid outline are in the upper level of thecircle and those shown in dashed outline are in the lower level of theintersection.

Referring to Figure 2, there is shown a slightly modiiied form ofcircle. In this case, each of the Winding lanes extends a suicientdistance to feed directly to the outgoing street from all down ramps,thus eliminating the lane 29 in the other intersection which proceedsalong the outboard portion of the winding lanes to the next clockwiselane. Thus, taking lane 4i) by Way of example, it will be noted thattraic enters this lane from street 41 by passing under the outer bridge42 and then on to the upper level which is represented by solid lanes.Proceeding along lane 40 it will be noted that traic may drop to thelower level along ramp 43 to reach street 44. In like manner traic maydrop on ramp 45 to reach street 46, ramp 47 to reach street 48, ramp 49to reach street 50, ramp 51 to reach street 52, and ramp 53- to reachstreet 54; It will be noted that the ramps proceed to the lower levelandv traic from the three outboard ramps ofv each group merge into asingle line of outgoing traic while traft'lcfrom the three inboardYramps of each group merges into a second single line of outgoingtraflic. Truck and right turn traine to adjacent streets are handled onbridge 4Z in the same manner as explained in connection with Figure l.

The form of invention shown in Figure 2 provides for merging of trafcwhile leaving the circle, thus reducing trafiic to five lanesimmediately upon reaching the street. Merging turning traffic isundesirable, and the Figure l form of invention which has a large numberof outgoing lanes is preferred. Of course, the seven outgoing lanes maybe merged int/ thiee outgoing lanes immediately after leaving thecircle, preferably in a progressive manner to reduce lto lane traic oneach street.

Referring now to Figure 3, there is shown a traffic circle constructedin accordance with this invention which follows generally the Figure 1embodiment except that there are four streets serviced by the circle andthe upper level of the Figure linters'ection is replaced by fourindividual bridgsSS, 56, 57 and 58. y Y

Each section of the'intersection is identical and, therefore, traicmovement from only one street will be traced.

Considering traic owing intothe tr'ac circle from street 59, provisionis made f or rright turn` t'raiiick by the U-shaped lane 61 whichreceives tratric from the curb lane of street 59 and discharges suchtraffic onto street 62;

Traic desiring to exit on either streets 63 or 64 proceeds on inboundlane 65 of street S9 to the traiic circle. As lane 65 reaches thecircle, it is conveyed across thev other traic of the circle at thispoint at a different elevation, such as by bridge 5 5.

From bridge 55 incoming trahie proceeds along lane 66 of the tra'fhccircle. This lane extends less than 36() degrees, in the caset asymmetrical intersection approxi= matelyA degrees, to street 64;

`As lane 66 of tlie traffic circle reaches the next adjacent street 63,it crosses the incoming trahie from street 63 at a diierent level as bybridge S6 which con; Veys the incoming trahie from street 63 over lane66. After passing" through bridge 56, thetrafc in lane 66 may divideVand turn left into lane 67 to proceed ontbound on street 63 or mayproceed to the right on a continuation of lane 66 to street 64.

As traic in lane 66 reaches .st-reet 64, it again crosses the incomingtraffic at aA different level as by bridge 57 and empties onto street 64in llane 68.

From the abovev it will be seen that there hasV been provided a verysimple four-street intersection in which there is no merging traiiic andin which only four bridges are needed to convey traic to and from eachintersection without merging traffic.

The foregoing' disclosure and description of the irrvention isillustrative andeirplanatoryfthereof and vari= ous changes may be' madewithin the scope of the appended claims without departing from thespiritV of the invention.

I claim:

l. A traflic' interchange comprising, a `traffic circle and a pluralityof streets radiating therefrom, said traf'- fic circle comprising, aplurality of spiraling side-byside lanes on one level, each of saidlanes beginning at the outboard of said circle at progressively spacedpoints,-

outboard of said circle at progressively spaced points in' the vicinityof' said radiating streets, entranceramps interconnecting each of saidstreets with the outboard eains.

end of a corresponding spiraling lane, and exit ramps departing fromspaced points on each of said spiraling lanes and connecting each ofsaid spiraling lanes with a plurality of said radiating streets, each ofsaid exit ramps crossing the contiguous spiraling lanes outboard of saidspaced points at an elevation diierent from the elevation of thespiraling lanes.

3. A traffic interchange comprising, a traflic circle and a plurality ofstreets radiating therefrom, said trafiic circle comprising, a pluralityof spiraling side-byside lanes on an upper level, each of said lanesbeginning at the outboard of said circle at progressively spaced pointsin the vicinity of said radiating streets, entrance rampsinterconnecting each of said streets with the outboard end of acorresponding elevated lane, and downwardly extending exit lanesdeparting from spaced points on each of said spiraling lanes andconnecting each of said spiraling lanes with a plurality of saidradiating streets, each of said downwardly extending ramps passing underthe contiguous elevated lanes outboard of said spaced points.

4. The traffic interchange of claim 3 wherein all of the exit rampsleading from the spiraling lanes at one angular position about thecircle with the exception of the exit ramp servicing the inboardspiraling lane leading to one street, said ramp servicing the inboardspiraling lane extending to the exterior of the circle and thence aboutthe circle to the next adjacent street.

5. The trac interchange of claim 3 wherein the spiraling lanes spiraltoward the center in one circular direction and a lane extends in theopposite direction References Cited in the le of this patent UNITEDSTATES PATENTS 1,543,080 Graves .Tune 23, 1925 1,689,161 Skultin f Oct.23, 1928 FOREIGN PATENTS 546,268 France Aug. 17, 1922 686,433 FranceApr. 14, 1930 736,887 Germany July 1, 1943 940,788 France Tune 7, 1948806,019 Germany June 11, I1951 OTHER REFERENCES Roads and Streets, pp.205-206, May 1932.

A Policy on Arterial Highways in Urban Areas, Bur. Public Roads, July1956, Figs. J-19(a) and J-l9(c).

A Policy on Arterial Highways in Urban Areas, American Assoc. of StateHighways, 1957, page 511.

Engineering News-Record, July 11, 1957, pp. 38 and 39.

